1. Field of the Invention
The present invention is filed claiming the priority of Japanese Patent Application No. 2011-078767 filed on Mar. 31, 2011 under the Paris Convention, the entire content of which is incorporated herein by reference.
The present invention relates to a process for producing a modified conjugated diene-based polymer, a modified conjugated diene-based polymer, and a polymer composition.
2. Description of Related Art
In recent years, with an increase of interest in the environmental problems, fuel cost saving has been strongly required on automobiles, and a rubber composition used in tires for automobiles is also required to be excellent in the fuel cost saving effect. As the rubber composition for tires for use in automobiles, a rubber composition containing a conjugated diene-based polymer such as polybutadiene or a styrene-butadiene copolymer, and a reinforcing agent has been used. Use of a silica reinforcing agent in place of carbon black, which has previously been used as a reinforcing agent, has been studied in order to improve performance as a rubber composition for tires.
Since the silica reinforcing agent has lower affinity with the conjugated diene-based polymer as compared with carbon black, it is necessary to enhance affinity between the silica reinforcing agent and the conjugated diene-based polymer in order to enhance the fuel cost saving effect. In order to enhance affinity between the silica reinforcing agent and the conjugated diene-based polymer, for example, JP-A-10-7702 proposes a method of polymerizing isoprene and butadiene as monomer components using n-butyllithium, reacting the resulting polymer with n-butyllithium to perform metallization, and thereafter, reacting the resultant with chloropropyltriethoxysilane to obtain a modified conjugated diene-based polymer.